Osteoporosis in men treated with androgen suppression therapy for prostate cancer

Cancer Treatment–Induced Bone Loss and Role of Denosumab in Nonmetastatic Prostate Cancer: A Narrative Review

Bone loss is an important complication of prostate cancer and its associated treatments, especially androgen-deprivation therapy (ADT). There is a 5 to 10 times increased loss of bone mineral density (BMD) in men receiving ADT with yearly 4 to 13% BMD loss. The risk of fracture increases yearly by 5 to 8% with ADT. ADT associated bone loss of 10 to 15% of BMD doubles the risk of fractures. Hence, BMD evaluation through dual-energy X-ray absorptiometry and evaluation of individual fracture risk assessed before initiating ADT. The use of vitamin D, calcium, bisphosphonates, and denosumab has shown improved bone health in men with prostate cancer receiving ADT. Denosumab 60 mg is approved to increase bone mass in men at high risk for fractures receiving ADT for nonmetastatic prostate cancer. Denosumab has shown improvement of 5.6% BMD at 2 years in nonmetastatic prostate cancer patients, with significant improvements seen at the total hip, femoral neck, and distal third of the radius. Denosumab has shown a 62% decreased incidence of new vertebral fractures at 36 months. Furthermore, denosumab delays the onset of bone metastases in high-risk nonmetastatic prostate cancer patients. Denosumab can be preferred over other bone modifying agents owing to several advantages, such as subcutaneous administration and no requirement of hospitalization, no dose modifications in renal impairment and less incidence of acute phase anaphylactic reactions. We review the available evidence of denosumab for managing bone loss in nonmetastatic prostate cancer patients. The relevant articles used in this narrative review were obtained through general search on google and PubMed using the key terms “non-metastatic prostate cancer,” “denosumab,” “bone loss,” “bone mineral density,” “fracture,” “CTIBL,” and “chemotherapy induced bone loss.”

Effects of voluntary wheel running on goserelin acetate-induced bone degeneration

A common treatment option for many breast and prostate cancer patients is the use of a luteinizing hormone-releasing hormone agonist such as goserelin acetate (GA) which reduces sex hormone levels. This treatment, however, is associated with bone degeneration, and exercise has been suggested as a means of preventing this side effect. Little is known about the effects of low intensity, low volume exercise on GA-induced bone loss. The purpose of this study, therefore, was to investigate the effects of voluntary wheel running on bone architecture in growing male (M) and female (F) rats receiving GA treatment. Rats received an 8-week GA treatment or placebo (CON) and were either housed in cages equipped with voluntary running wheels (WR) or remained sedentary (SED) in standard cages throughout the experimental period. Following treatments, tibiae were excised and analyzed for cortical bone (cross-sectional volume, cortical volume, marrow volume, cortical thickness) and cancellous bone (bone volume/total volume, trabecular number, trabecular thickness, trabecular spacing) using micro-computed tomography. Treatment with GA resulted in a significant reduction in running wheel distances in both sexes throughout the study period (P<0.05). GA treatment had no effect on cortical bone architecture in neither sex (P>0.05). Cancellous bone degeneration, however, was observed in M and F SED+GA (P<0.05). No significant differences were observed in M WR+GA animals in bone volume/total volume, trabecular number and trabecular spacing when compared to M SED+CON (P>0.05). In F WR+GA, trabecular thickness did not differ from that of F SED+CON (P>0.05), and trabecular spacing was found to be significantly lower than F SED+GA (P<0.05). The current report indicates that 8 weeks of GA treatment promotes cancellous bone degeneration, and voluntary wheel running provides no clear osteoprotection in growing male and female rats.

Bone Mineral Density and its Related Factors in Elderly Male Chinese Patients with Type 2 Diabetes

BACKGROUND

There have been few investigations conducted on the epidemiology and risk factors of osteoporosis in patients with diabetes in China. The aim of this study was to disclose the percentage and the possible risk factors that influence bone mineral density (BMD) in this population.

METHODS

One hundred thirty-one elderly male patients with type 2 diabetes (73.12 +/- 5.54 years of age, diabetic duration 5.28 +/- 3.56 years, HbA(1C) 7.87% +/- 1.82 %), >65 years of age were recruited. All subjects were submitted to dual-energy X-ray absorptiometry to evaluate the BMD at lumbar spine (LS), femoral neck (FN), and femoral trochanter (FT). Fasting blood samples were taken to check hormones and biochemical levels. Demographic data were also collected.

RESULTS

In the different bone sites studied, the percentage of osteoporosis and osteopenia varied in this group of patients ranging from 29.0 to 31.3% and 29.0 to 33.6%, respectively. Weight, HbA(1C), body mass index, and testosterone were correlated with BMD at all the bone sites studied. Weight was the best predictor among the above parameters for BMD by linear regression analysis at LS and FN, whereas testosterone was the best predictor for BMD at FT.

CONCLUSIONS

In the different bone sites studied, the percentage of osteoporosis and osteopenia varied ranging from 29.0 to 31.3% and 29.0 to 33.6%, respectively. Weight was the best predictor for BMD at LS and FN and testosterone was the best predictor for BMD at FT. Poor glycemic control was correlated with osteoporosis.

Hormone-Refractory Prostate Cancer: A Shifting Paradigm in Treatment

Prostate cancer, the most common male cancer, affects one in eight American men. Risk factors for the disease include increased age, race, and family history of prostate cancer. To date, surgery, radiation, and hormonal therapy have been the mainstays of treatment. In the past, chemotherapy served only a palliative role for men with prostate cancer and failed to produce a survival advantage or any significant measurable disease response. However, for the first time, docetaxel-based regimens have demonstrated improved survival in men with hormone-refractory prostate cancer in two different, large, phase III studies. Additionally, a number of novel agents are being developed with the hope that treatment for men with hormone-refractory prostate cancer will be improved. Oncology nurses provide critical symptom management strategies as well as education to men with prostate cancer and their partners. Therefore, maintaining current state of the knowledge about best practices and treatment for prostate cancer is crucial. This, in turn, directs efforts to educate patients and family members about treatments and management of side effects.

Inhibition of androgen-independent prostate cancer by estrogenic compounds is associated with increased expression of immune-related genes

The clinical utility of estrogens for treating prostate cancer (CaP) was established in the 1940s by Huggins. The classic model of the anti-CaP activity of estrogens postulates an indirect mechanism involving the suppression of androgen production. However, clinical and preclinical studies have shown that estrogens exert growth-inhibitory effects on CaP under low-androgen conditions, suggesting additional modes whereby estrogens affect CaP cells and/or the microenvironment. Here we have investigated the activity of 17beta estradiol (E2) against androgen-independent CaP and identified molecular alterations in tumors exposed to E2. E2 treatment inhibited the growth of all four androgen-independent CaP xenografts studied (LuCaP 35V, LuCaP 23.1AI, LuCaP 49, and LuCaP 58) in castrated male mice. The molecular basis of growth suppression was studied by cDNA microarray analysis, which indicated that multiple pathways are altered by E2 treatment. Of particular interest are changes in transcripts encoding proteins that mediate immune responses and regulate androgen receptor signaling. In conclusion, our data show that estrogens have powerful inhibitory effects on CaP in vivo in androgen-depleted environments and suggest novel mechanisms of estrogen-mediated antitumor activity. These results indicate that incorporating estrogens into CaP treatment protocols could enhance therapeutic efficacy even in cases of advanced disease.

Cancer-treatment-induced bone loss, part 1

PURPOSE

The pathophysiology, frequency, sequelae, diagnosis, and treatment of cancer-treatment-induced bone loss (CTIBL) are discussed.

SUMMARY

CTIBL is a long-term complication associated with cancer therapies that can directly or indirectly affect bone metabolism. Although CTIBL can occur in any patient receiving a cancer therapy known to cause bone loss, CTIBL is most common in patients with breast or prostate cancer who receive chemotherapy, hormone therapy, or surgical castration, as these can cause hypogonadism and induce bone loss. CTIBL causes bone fragility and an increased susceptibility to fractures; therefore, prevention, early diagnosis, and treatment of CTIBL are essential to decrease the risk of fracture. Bone loss occurs more rapidly and tends to be more severe in patients with CTIBL compared with those with normal age-related bone loss. Fractures of the hip, vertebra, and wrist are the fractures most commonly associated with bone loss. CTIBL is diagnosed by measuring bone mass using bone densitometry. Treatment of CTIBL consists of changing diet and lifestyle such as optimizing calcium and vitamin D intake, exercising, modifying behaviors known to increase the risk of CTIBL and pharmacologic therapy with hormone replacement therapy (HRT), selective estrogen-receptor modifiers (SERMs), calcitonin, or a bisphosphonate.

CONCLUSION

Early identification and treatment of CTIBL are essential to prevent fractures. Patients should be instructed to optimize calcium and vitamin D intake, exercise regularly, and modify lifestyle behaviors known to cause bone loss. Patients with CTIBL should be treated with an oral or i.v. bisphosphonate; SERMs or HRT may be an option in some patients if contraindications do not exist.

Cancer treatment-induced bone loss in patients with breast or prostate cancer

PURPOSE/OBJECTIVES

To review the prevalence, consequences, pathophysiology, diagnosis, and treatment of cancer treatment-induced bone loss (CTIBL) in patients with breast or prostate cancer.

DATA SOURCES

Published articles, abstracts, book chapters, electronic resources, and manufacturer information.

DATA SYNTHESIS

CTIBL is a long-term complication associated with cancer therapies that cause hypogonadism in patients with breast or prostate cancer. Early diagnosis and treatment of CTIBL is essential to prevent bone fractures. CTIBL treatment includes modification of lifestyles that increase the risk of developing bone loss and fractures and includes the use of bone loss therapies (e.g., bisphosphonates, selective estrogen receptor modifiers, calcitonin).

CONCLUSIONS

CTIBL is becoming more common as patients with breast or prostate cancer survive longer. Identifying and treating CTIBL early are important because once bone is lost, damaged bone becomes more difficult to repair; early diagnosis and treatment also may prevent fractures.

IMPLICATIONS FOR NURSING

Nurses must be knowledgeable about CTIBL to identify high-risk patients and educate patients and their families about CTIBL, bone loss therapies, and lifestyle modifications.

Osteoporosis: Incidence, Prevention, and Treatment of the Silent Killer

Osteoporosis is a nationwide health care concern affecting millions of Americans. Health care dollars to prevent and treat osteoporosis are needed. Osteoporosis-related injuries and resulting disabilities, and consequent admissions to hospitals, nursing homes, and long-term care facilities is costing billions of dollars for care and treatment. Healthy lifestyle choices including vitamin and mineral therapy; safe home environments; a diet replete with calcium, vitamin D, and protein; weight-bearing and resistance exercises; and fall prevention programs for home-bound and hospitalized elders are needed to prevent osteoporosis-related fractures and injuries. Nurses must educate the public on osteoporosis and osteoporosis-prevention activities. Research in nursing, pharmacy, and allied health fields such as physical therapy and nutrition must expand to improve understanding of the risks associated with osteoporosis and to evaluate health-promotion and disease- prevention activities. Interdisciplinary partnerships should be established to study the issues, prevention, and treatment modalities of this "silent killer."

Bisphosphonates: expanded roles in the treatment of patients with cancer

Bisphosphonates are important inhibitors of osteoclastic bone resorption seen in patients with bone metastases associated with malignancy. Bisphosphonates are used in the treatment of patients with bone metastases and have been shown to reduce skeletal-related events and symptoms, contributing to improved patient outcomes and quality of life. These agents first were approved in the treatment of patients with osteoporosis and have been used for the past two decades in this role. Because bisphosphonates inhibit osteoclast-mediated bone resorption, the bone remodeling cycle slows down and an increase in bone mineral density occurs. These agents are useful in treatment for both hypercalcemia and pain, although they have not definitively shown improvement in survival time. Considerable interest exists in the use of bisphosphonates for prevention of bone metastases and their potential antitumor activity. These drugs are well tolerated and have minimal side effects, but they are not inexpensive. This article discusses the role of bisphosphonates in patients with cancer and future directions for further research.

Bisphosphonates: their evolving role in the management of prostate cancer-related bone disease

PURPOSE OF REVIEW

The use of androgen deprivation therapy has increased because of its use as part of multimodality therapy for high-risk early stage disease and in recurrent nonmetastatic disease. Hormonal therapy is associated with secondary osteoporosis and increased skeletal morbidity. Furthermore, in patients with established bone metastases, osseous complications are a significant problem. Bisphosphonates have been investigated in the prevention of bone density loss and skeletal morbidity. Results of these studies are now becoming available.

RECENT FINDINGS

Data are emerging that demonstrate that bisphosphonates can prevent skeletal morbidity, such as pathologic fractures and spinal cord compression in men with hormone-refractory prostate cancer. The early use of bisphosphonates has also been shown to prevent bone loss due to androgen deprivation therapy. Current third-generation bisphosphonates are several hundred times more potent than their predecessors. Evidence is emerging that these drugs not only inhibit bone resorption but also are cytotoxic to prostate cancer cells.

SUMMARY

Bisphosphonates are assuming a prominent ancillary role in prostate cancer therapy through their ability to prevent skeletal morbidity. Their potential to interfere with the formation of osseous tumor deposits has lead to investigations into the capacity of these drugs to prevent bone metastasis.